Regional relationships between climate and wildfire-burned area in the Interior West, USA
نویسندگان
چکیده
Recent studies have linked the Atlantic Mdtidecadal Oscillation (AMO) and the Pacific Decadal Oscillation (PDO) with drought occurrence in the interior United States. This study evaluates the influence of AM0 and PDO phases on interannual relationships between climate and wildfire-burned area during the 20th century. Palmer's Drought Severity Index (PDSI) is strongly related to burned area at both regional and subregional scales. In the southern Interior West, PDSI is most strongly related to yearly burned area during warm-phase AMO, while for the same period no significant relationships exist between PDSI and burned area in the central Interior West. During cool-phase PDO, interannual climate has little influence on burned area in either the northern or the central Interior West. The opposite is true for the southern Interior West and the eastern slope of the Colorado Rockies using the Southern Oscillation Index and PDSI, respectively. The western slope of the Colorado Rockies is the only climate division or region in which burned area is not related to preceding PDSI. During warm-phase PDO, current PDSI explains 67% of the interannual variance in burned area on the western slope. These regional and temporal differences are most likely governed by variations in fuel dynamics associated with dominant regional and subregional vegetation types. Resum6 : Des Ctudes rCcentes ont Ctabli un lien entre l'oscillation multi-dkcennale de lxtlantique (OMA), l'oscillation dkcennale du Pacifique (ODP) et les p6riodes de secheresse dans les @ions interieures aux ha ts -~nis . Cette etude evalue l'influence des phases de 1'OMA et de I'ODP sur les relations entre le climat et les superficies b a b e s annuellement pendant le 20C sikcle. L'indice de skvtrit6 de sCcheresse de Palmer (ISSP) est Btroitement relit aux superficies b a i e s tant B I'Cchelle rigionale que sub-rtgionale. Dans le sud de la rCgion int6rieure ouest, I'ISSP est le plus btroitement relit5 aux superficies bil6es durant la phase chaude de I'OMA alors qu'il n'y a pas de relation significative entre 1'ISSP et les superficies briilCes dans le centre de la rCgion inttrieure ouest durant la m&me $riode. Pendant la phase froide de l'ODP, le climat a peu d'influence sur les supeficies b d 6 e s annuellement tant dans le nord que dans le centre de la region intCrieure ouest. Le contraire est vrai pour le sud de la region int6rieure ouest et le versant est des Rocheuses au Colorado en utilisant respectivement l'indice d'oscillation m6ridionale (IOM) et 1'lSSP. Le versant ouest des Rocheuses au Colorado est la seule &$on clirnatique oil les superficies b i l&s ne sont pas reliees ?i 1'ISSP antkrieur. Durant la phase chaude de I'ODP, I'ISSP explique 67 % de la variation dans les superficies brCLltes d'une annCe l'autre sur le versant ouest. Ces diff6rences rkgionales et temporelles sont fort probablement dkterminbes par les variations dans la dynamique des combustibles associ6s aux types de vtg6tation qui dominent ?i 1'Cchelle dgionale et sub-figionale. [Traduit par la Redaction]
منابع مشابه
Running head : CLIMATE AND ECOPROVINCE FIRE AREA BURNED 1 2 CLIMATE AND WILDFIRE AREA BURNED IN WESTERN U
23 We demonstrate that wildfire area burned (WFAB) in the American West was significantly 24 controlled by climate (combinations of precipitation, temperature, and/or drought) during most 25 of the 20 century (1916-2003). Persistent, ecosystem-specific correlations between climate 26 variables and area burned are grouped by vegetation type for 16 ecoprovinces across the West. 27 Most mountainou...
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